Fish Pen Penicillin 500mg – 60 Tablets

Fish Pen (Penicillin) Tablets are a dependable broad-spectrum antibiotic designed for aquarium fish. Fish Pen targets gram-positive bacterial infections such as fin rot, gill disease, mouth rot, and skin lesions, delivering fast-acting relief and improved aquatic health.

Perfect for both beginner and experienced aquarists, Fish Pen is safe for use in freshwater and saltwater aquariums and dissolves quickly for even treatment distribution. Restore your fish’s health and prevent the spread of infections with this essential fish medication.

Key Benefits

• Broad Spectrum of Action: Effective against gram-positive bacteria like Streptococcus and Aeromonas species.
• Effective Against Common Infections: Treats fin rot, gill disease, mouth fungus, and other bacterial conditions.
• Easy Application: Tablets dissolve quickly in water for simple dosing or can be applied with food.
• Fast Healing Support: Reduces fish stress and promotes visible recovery within days.
• Limits Infection Spread: Stops infections before they can affect other healthy fish in your tank.

Directions for Use

• Add one 500mg tablet per 20 gallons of aquarium water.
• Repeat dosage every 24 hours for 5–10 days depending on the severity of the infection.
• Make a partial water change between treatments to maintain water quality.
• If no improvement is seen within 5 days, stop use and consult a veterinarian or aquarist.

Storage Instructions

• Store tightly closed at 59°–86°F (15°–30°C) in a cool, dry place.
• Keep out of reach of children and pets.
• Do not use after expiration date printed on packaging.

Important Cautions

• For ornamental aquarium use only. Not for use with fish intended for human consumption.
• Remove shrimp, snails, and other invertebrates prior to treatment as Penicillin may harm them.
• Monitor ammonia, nitrite, and nitrate levels during treatment to ensure healthy tank balance.

Shipping & Returns

Shipping: We offer Ground, Express, Priority, and International shipping options. View shipping policy.

Returns: Having an issue? Review our refund policy for return instructions.

FAQs – Fish Pen Penicillin 500mg 60 Tablets

What infections does Fish Pen treat?

It treats gram-positive bacterial infections including fin rot, gill disease, mouth fungus, and columnaris.

Can I use it in saltwater aquariums?

Yes, Fish Pen is safe for both saltwater and freshwater tanks.

Is it safe for shrimp and snails?

No. Remove invertebrates during treatment to avoid harm.

Does it impact beneficial bacteria?

Yes, to a degree. Monitor water quality and supplement beneficial bacteria post-treatment if needed.

Will it discolor water?

No, Fish Pen dissolves clearly and does not affect tank appearance.

Can I use Fish Pen for betta fish?

Yes, but ensure the proper dosage is used based on smaller tank volumes.

Does Fish Pen expire?

Yes, always check the expiration date and use before it passes.

Is it safe for planted aquariums?

Generally, yes. Fish Pen does not harm most common aquarium plants.

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